The purpose of the work described in this proposal is to continue study of the mechanisms of cellular immunity and hypersensitivity. Our aim is to acquire knowledge of basic mechanisms which can be used to rationally manipulate these cellular processes in certain human clinical conditions of disease such as infections or neoplasia, or where suppression might diminish tissue injury caused by cellular hypersensitivity. The proposed investigation is a direct outgrowth of our interests in the interaction of lymphocytes, their mediators and macrophages in cellular immunity. Studies in this project will include further investigations of the mechanisms of macrophage activation by lymphocyte mediators, analysis of the glycolipid and glycoprotein content of purified macrophage membrane preparations obtained from activated and control macrophages, further purification of migration inhibitory factor, studies on the relationship of mouse MIF and SIRS, a mediator which inhibits antibody formation in vitro and also acts via macrophages, and studies on the mechanism of human transfer factor. BIBLIOGRAPHIC REFERENCES: Walker, A.M., Garcia, R., Pate, P., Mata, L.J., and David, J.R.: Transfer factor in the immune deficiency of protein- calorie malnutrition: a controlled study with 32 cases. Cell. Immunol. 15: 372, 1975. David, J.R.: A brief review of macrophage activation by lymphocyte mediators. In: THE PHAGOCYTIC CELL IN HOST RESISTANCE, Dayton and Belanti, eds., Raven Press, 1975.